The present invention relates to a partitioned switching panel. More particularly, the present invention relates to partitioned switching panel of the type which includes a power switch which is mounted on a carriage or the like so that the power switch can be moved toward and away from stationary switch contacts disposed behind a partition of the panel and accessible through openings which are closed by displaceable shutters when the power switch is in the circuit breaking position, and wherein the opening and closing mechanism for the shutters comes into engagement with the forward drive of the power switch carriage and is actuated by same when the power switch carriage is in the circuit breaking position.
A partitioned switching panel of the above type is disclosed in Swiss Patent No. 558,600, issued Dec. 15th, 1974 and comprises a lever which is rotationally mounted on the switching panel and is provided with a cam follower as well as a crank fixed to the housing as part of the forward drive, and with a pivot plate rotationally mounted in the housing as the connection member for the opening and closing mechanism of the shutters. The parts are configured in such a way that actuation of the forward drive from the circuit breaking position, with the shutters closed, causes only part of the switch closing path to be traversed. Subsequently, when the switching carriage is stopped, the shutters are opened and then the second part of the path is traversed until the operating position of the switch is reached.
This sequence of movements has the drawback that the switching panel has a relatively large depth and thus takes up a large base surface in the plant. Additionally it requires a crank which has several bends that are expensive in manufacture and inevitably must cooperate with a relatively long lever, since the movement of the switching carriage between the circuit breaking and the operating position causes the cam follower of the lever to be unable to move through the crank in both directions, due to the bends in the crank. As a further drawback, this long lever arm transmits high torques to the forward drive, primarily during movement of the power switch into the stationary circuit breaker contacts, but also as a reaction to high shortcircuit currents flowing through the power switch.
A partitioned switching panel of the above type is also disclosed in U.S. Pat. No. 2,673,260 issued Mar. 2nd, 1954 wherein the problem of large dimensions of the above discussed references is generally overcome in that the forward drive for the carriage and the opening and closing mechanism cooperate with one another in a manner such that the opening of the shutters is completed when the forward movement of the carriage from the circuit breaking position to the connected position begins. According to this patent, this is achieved by providing the drive mechanism with an orbital cam follower which cooperates with a relatively complex camming surface formed in a specially formed hooked racking cam plate in order to provide for lost motion in the racking or movement of the carriage during the time the shutters are opened.